A hand-operated pump has been normally used in bath goods or cosmetics containers that discharge a predetermined amount of liquid, emulsion, or oil content each time because of its convenience. Especially, the hand-operated pump has been widely used because of its characteristics that a predetermined amount of content can be easily discharged each time by the hand-operated pump while the content is stored in the container, and technology related to the hand-operated pump has been continuously developed.
A conventional hand-operated spray pump mainly includes a housing forming the external appearance of the pump, a closure used to mount the housing to a container, a stem communicating with a discharge port formed at a button and configured to be moved upward and downward along the housing, a shaft configured to guide the upward and downward movement of the stem and to connect the stem to the button, a housing cap configured to guide upward and downward movement of the shaft and to seal the internal space of the housing from the outside, a piston mounted to the stem such that the piston can be moved upward and downward along the inner wall of the housing, a compression spring mounted to the inner lower part of the housing, and a ball configured to open and close an inlet port formed at the lower end of the housing.
However, the conventional hand-operated spray pump has several problems as follows:
First, the compression spring is located on the route along which the content flows, with the result that the compression spring comes into contact with the content. Consequently, it is difficult for the content to flow due to the compression spring. That is, flow resistance to the content is increased by the compression spring. Also, the compression spring may be deteriorated. In this case, the content may also be deteriorated.
Second, a residual portion of the content is present at the discharge port of the button after pumping the content, which is not preferable in view of sanitation. Also, if such content exhibits low viscosity, the content may fall or be solidified, thus clogging the discharge port of the button.
Third, sealability with respect to the content in the container is increasingly reduced due to repetitive pumping. Especially when a pump containing oil for cleansing cosmetics and beauty products is used, the content does not leak at first due to spreadability of the oil; however, leakage of the content occurs with the passage of time.
Various structures have been developed to solve the above problems; however, there is no hand-operated spray pump providing satisfactory results yet. For this reason, there is high necessity for technology that is capable of fundamentally solving the above problems.